/*
 * contrib/btree_gist/btree_bit.c
 */
#include "postgres.h"

#include "btree_gist.h"
#include "btree_utils_var.h"
#include "utils/builtins.h"
#include "utils/bytea.h"
#include "utils/varbit.h"


/*
** Bit ops
*/
PG_FUNCTION_INFO_V1(gbt_bit_compress);
PG_FUNCTION_INFO_V1(gbt_bit_union);
PG_FUNCTION_INFO_V1(gbt_bit_picksplit);
PG_FUNCTION_INFO_V1(gbt_bit_consistent);
PG_FUNCTION_INFO_V1(gbt_bit_penalty);
PG_FUNCTION_INFO_V1(gbt_bit_same);


/* define for comparison */

static bool
gbt_bitgt(const void *a, const void *b, Oid collation, FmgrInfo *flinfo)
{
    return DatumGetBool(DirectFunctionCall2(bitgt,
                                            PointerGetDatum(a),
                                            PointerGetDatum(b)));
}

static bool
gbt_bitge(const void *a, const void *b, Oid collation, FmgrInfo *flinfo)
{
    return DatumGetBool(DirectFunctionCall2(bitge,
                                            PointerGetDatum(a),
                                            PointerGetDatum(b)));
}

static bool
gbt_biteq(const void *a, const void *b, Oid collation, FmgrInfo *flinfo)
{
    return DatumGetBool(DirectFunctionCall2(biteq,
                                            PointerGetDatum(a),
                                            PointerGetDatum(b)));
}

static bool
gbt_bitle(const void *a, const void *b, Oid collation, FmgrInfo *flinfo)
{
    return DatumGetBool(DirectFunctionCall2(bitle,
                                            PointerGetDatum(a),
                                            PointerGetDatum(b)));
}

static bool
gbt_bitlt(const void *a, const void *b, Oid collation, FmgrInfo *flinfo)
{
    return DatumGetBool(DirectFunctionCall2(bitlt,
                                            PointerGetDatum(a),
                                            PointerGetDatum(b)));
}

static int32
gbt_bitcmp(const void *a, const void *b, Oid collation, FmgrInfo *flinfo)
{
    return DatumGetInt32(DirectFunctionCall2(byteacmp,
                                             PointerGetDatum(a),
                                             PointerGetDatum(b)));
}


static bytea *
gbt_bit_xfrm(bytea *leaf)
{
    bytea       *out = leaf;
    int            sz = VARBITBYTES(leaf) + VARHDRSZ;
    int            padded_sz = INTALIGN(sz);

    out = (bytea *) palloc(padded_sz);
    /* initialize the padding bytes to zero */
    while (sz < padded_sz)
        ((char *) out)[sz++] = 0;
    SET_VARSIZE(out, padded_sz);
    memcpy((void *) VARDATA(out), (void *) VARBITS(leaf), VARBITBYTES(leaf));
    return out;
}




static GBT_VARKEY *
gbt_bit_l2n(GBT_VARKEY *leaf, FmgrInfo *flinfo)
{
    GBT_VARKEY *out = leaf;
    GBT_VARKEY_R r = gbt_var_key_readable(leaf);
    bytea       *o;

    o = gbt_bit_xfrm(r.lower);
    r.upper = r.lower = o;
    out = gbt_var_key_copy(&r);
    pfree(o);

    return out;

}

static const gbtree_vinfo tinfo =
{
    gbt_t_bit,
    0,
    TRUE,
    gbt_bitgt,
    gbt_bitge,
    gbt_biteq,
    gbt_bitle,
    gbt_bitlt,
    gbt_bitcmp,
    gbt_bit_l2n
};


/**************************************************
 * Bit ops
 **************************************************/

Datum
gbt_bit_compress(PG_FUNCTION_ARGS)
{
    GISTENTRY  *entry = (GISTENTRY *) PG_GETARG_POINTER(0);

    PG_RETURN_POINTER(gbt_var_compress(entry, &tinfo));
}

Datum
gbt_bit_consistent(PG_FUNCTION_ARGS)
{
    GISTENTRY  *entry = (GISTENTRY *) PG_GETARG_POINTER(0);
    void       *query = (void *) DatumGetByteaP(PG_GETARG_DATUM(1));
    StrategyNumber strategy = (StrategyNumber) PG_GETARG_UINT16(2);

    /* Oid        subtype = PG_GETARG_OID(3); */
    bool       *recheck = (bool *) PG_GETARG_POINTER(4);
    bool        retval;
    GBT_VARKEY *key = (GBT_VARKEY *) DatumGetPointer(entry->key);
    GBT_VARKEY_R r = gbt_var_key_readable(key);

    /* All cases served by this function are exact */
    *recheck = false;

    if (GIST_LEAF(entry))
        retval = gbt_var_consistent(&r, query, strategy, PG_GET_COLLATION(),
                                    TRUE, &tinfo, fcinfo->flinfo);
    else
    {
        bytea       *q = gbt_bit_xfrm((bytea *) query);

        retval = gbt_var_consistent(&r, q, strategy, PG_GET_COLLATION(),
                                    FALSE, &tinfo, fcinfo->flinfo);
    }
    PG_RETURN_BOOL(retval);
}



Datum
gbt_bit_union(PG_FUNCTION_ARGS)
{
    GistEntryVector *entryvec = (GistEntryVector *) PG_GETARG_POINTER(0);
    int32       *size = (int *) PG_GETARG_POINTER(1);

    PG_RETURN_POINTER(gbt_var_union(entryvec, size, PG_GET_COLLATION(),
                                    &tinfo, fcinfo->flinfo));
}


Datum
gbt_bit_picksplit(PG_FUNCTION_ARGS)
{
    GistEntryVector *entryvec = (GistEntryVector *) PG_GETARG_POINTER(0);
    GIST_SPLITVEC *v = (GIST_SPLITVEC *) PG_GETARG_POINTER(1);

    gbt_var_picksplit(entryvec, v, PG_GET_COLLATION(),
                      &tinfo, fcinfo->flinfo);
    PG_RETURN_POINTER(v);
}

Datum
gbt_bit_same(PG_FUNCTION_ARGS)
{
    Datum        d1 = PG_GETARG_DATUM(0);
    Datum        d2 = PG_GETARG_DATUM(1);
    bool       *result = (bool *) PG_GETARG_POINTER(2);

    *result = gbt_var_same(d1, d2, PG_GET_COLLATION(), &tinfo, fcinfo->flinfo);
    PG_RETURN_POINTER(result);
}


Datum
gbt_bit_penalty(PG_FUNCTION_ARGS)
{
    GISTENTRY  *o = (GISTENTRY *) PG_GETARG_POINTER(0);
    GISTENTRY  *n = (GISTENTRY *) PG_GETARG_POINTER(1);
    float       *result = (float *) PG_GETARG_POINTER(2);

    PG_RETURN_POINTER(gbt_var_penalty(result, o, n, PG_GET_COLLATION(),
                                      &tinfo, fcinfo->flinfo));
}
